1. Field of the Invention
The present invention relates to liquid crystal modules used as display devices of electronic devices such as television receivers and microcomputers. More specifically, the present invention relates to a structure of an interconnect substrate for use in a liquid crystal module, the interconnect substrate having conductor traces for interconnecting a driver substrate on which a driver element for driving a liquid crystal cell is mounted and a controller substrate on which a control circuit for controlling the driver element is mounted.
2. Description of Related Art
In recent years, display devices using a liquid crystal module have come to be used increasingly widely as display devices of electronic devices such as television receivers and microcomputers for their advantages of being thin and lightweight, and consuming a low amount of power. The liquid crystal module, in general, has a built-in backlight light source consisting of a cold cathode tube and other parts, and irradiates a forward-mounted liquid crystal cell (also called a liquid crystal panel) with light emitted from the light source and passing through an optical sheet such as a diffusing plate and a prism sheet, letting the light pass through a color filter provided in the liquid crystal cell. In this way, color images are displayed on the display surface of the liquid crystal cell.
The operation of the liquid crystal cell of the liquid crystal module is controlled by a signal, and different driver elements and substrates are attached to the liquid crystal cell (see, for example, JP-A-2006-195225 and JP-B-3281861).
FIG. 5 is a schematic plan view illustrating the relationship between a conventional liquid crystal cell and different driver elements and substrates attached thereto. As shown in FIG. 5, a plurality of COFs (chips on film) 103, each having a source driver 102 mounted thereon for feeding a signal to the source of an unillustrated thin-film transistor (TFT) provided on a glass substrate of the liquid crystal cell 101, and a plurality of COFs 105, each having a gate driver 104 mounted thereon for feeding a signal to the gate of the thin-film transistor, are connected to the conventional liquid crystal cell 101.
The COFs 103 on which the source drivers 102 are mounted are connected to an interconnect substrate 106 for a source (hereinafter a “source interconnect substrate 106”). The source interconnect substrate 106 interconnects the COFs 103 on which the source drivers 102 are mounted and a controller substrate (not shown) on which a control circuit for controlling the source drivers 102 is mounted, and conductor traces for interconnecting these two substrates are formed therein. The COFs 105 on which the gate drivers 104 are mounted are connected to an interconnect substrate 107 for a gate (hereinafter a “gate interconnect substrate 107”). The gate interconnect substrate 107 interconnects the COFs 105 on which the gate drivers 104 are mounted and a controller substrate (not shown) on which a control circuit for controlling the gate drivers 104 is mounted, and conductor traces for interconnecting these two substrates are formed therein.
This is the structure of the conventional liquid crystal cell 101. Incidentally, due to a recent increase in demand for larger liquid crystal displays, the interconnect substrates 106 and 107 provided in the liquid crystal cell 101 are getting longer and longer. However, as the interconnect substrates 106 and 107 provided in the liquid crystal cell 101 become longer, problems arise, such as greater difficulty in handling them. It is for this reason that the interconnect substrates 106 and 107 have conventionally been divided into a plurality of parts. In particular, since the source interconnect substrate 106 is long in an X direction (see FIG. 5), which is a longer-side direction of the liquid crystal cell 101, the source interconnect substrate 106 may be divided into two interconnect substrates, of which one is a left-side interconnect substrate and the other is a right-side interconnect substrate. It is to be noted that, when the liquid crystal cell 101 shown in FIG. 5 is viewed from the front (from the side on which the display surface is located), the interconnect substrate disposed on the left side of a center line C and the interconnect substrate disposed on the right side thereof are the left-side interconnect substrate and the right-side interconnect substrate, respectively.
However, when the source interconnect substrate 106 provided in the liquid crystal cell 101 is divided into two interconnect substrates, of which one is a left-side interconnect substrate and the other is a right-side interconnect substrate, and the resultant interconnect substrates are disposed in position, the left-side interconnect substrate and the right-side interconnect substrate have to be produced separately. This unfavorably reduces production efficiency. This drawback will be described with reference to FIGS. 6A and 6B.
FIGS. 6A and 6B are schematic plan views showing the structures of two conventional interconnect substrates, of which one is a left-side interconnect substrate 106a (hereinafter an “L-side interconnect substrate 106a”) and the other is a right-side interconnect substrate 106b (hereinafter an “R-side interconnect substrate 106b”), into which the source interconnect substrate 106 is divided. FIG. 6A is a diagram showing the L-side interconnect substrate 106a, and FIG. 6B is a diagram showing the R-side interconnect substrate 106b. 
As shown in FIGS. 6A and 6B, the L-side interconnect substrate 106a and the R-side interconnect substrate 106b each include conductor traces (not shown) for interconnecting the aforementioned source driver 102 and controller substrate, a connector portion 111 having a connector pattern that provides electrical connection between the interconnect substrate and the controller substrate, connection portions 112 connected to the COFs 103 on which the source drivers 102 are mounted, and a terminating resistor portion 113 in which a terminating resistor connected to the ends of the conductor traces is disposed.
However, if the connector portion 111 and the terminating resistor portion 113 are formed in the right and left sides, respectively, of the L-side interconnect substrate 106a, they are formed in reverse positions in the R-side interconnect substrate 106b, and vice versa. As a result, the L-side interconnect substrate 106a and the R-side interconnect substrate 106b differ from each other in the configuration of the conductor traces for interconnecting the source driver 102 and the controller substrate.
The conventional L-side interconnect substrate 106a and R-side interconnect substrate 106b shown in FIGS. 6A and 6B are each secured, for example, to a rear frame (not shown) disposed behind the liquid crystal cell 101 (behind the display surface of the liquid crystal cell 101) by three screws. The L-side interconnect substrate 106a and the R-side interconnect substrate 106b differ from each other also in the positions of screw holes 114 through which the screws are placed (in the position of the middle of the three screw holes 114, the one encircled with dashed lines in FIGS. 6A and 6B).
Therefore, conventionally, it is necessary to produce the L-side interconnect substrate 106a and the R-side interconnect substrate 106b separately, and manage their parts separately. This reduces the efficiency of producing liquid crystal modules, resulting in an increase in workload and costs.